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Base Length (base + length)
Selected AbstractsVariability of tilapias (Oreochromis spp.) introduced in Mexico: morphometric, meristic and genetic charactersJOURNAL OF APPLIED ICHTHYOLOGY, Issue 1 2004I. D. L. A. Barriga-Sosa Summary In Mexico, the tilapia Oreochromis provides one of the most important sources of animal protein and income in a wide variety of communities throughout the country, however, their culture and production face severe problems because of lack of management information. Evaluated in the present study is the degree of morphological, meristic and allozyme variation of two tilapia strains, two species and one hybrid from two important reservoirs in Mexico, two tilapia fry production farms (TFPF) and an experimental production system (EPS), to diagnose the actual status and degree of variation among them. Twenty-two presumptive loci were utilized to determine the genetic variation, structuring and distances among samples. Multivariate analyses of 11 meristic and 33 morphometric characters were also evaluated, including the distance from the end of the mouth opening to the most anterior dorsal fin (0.9894), distance from the anal fin base to the anterior part of the caudal fin (0.9845) and the base length of the dorsal fin (0.9839) which contributed to the separation of groups. The canonical discriminant functions for the morphometric and meristic variables show that the correct classification of the organisms in percentages and in the sites of origin was on average 72%. The tilapia from the reservoirs and the experimental production system had higher genetic variations than tilapia from the fry production farms (average He 0.310, 0.062, 0.151 for Metztitlan, Infiernillo and EPS, respectively, vs 0.024 and 0.000 for Los Amates and Zacatepec, respectively). The genetic data indicate that fishes of the TFPF should be monitored closely, as they are the main source of dispersion to the reservoirs. Present results show that these data could be a fast and reliable aid to the fisheries and management of tilapia in Mexico. [source] Craniofacial morphology in patients with hypophosphataemic vitamin-D-resistant rickets: a cephalometric studyJOURNAL OF ORAL REHABILITATION, Issue 7 2009S. H. AL-JUNDI Summary, Hypophosphataemic vitamin-D-resistant rickets (HVDRR) is a hereditary disease mainly transmitted as an X-linked dominant trait and characterized by certain general clinical signs (Filho HM, de Castro LC, Damiani D. Arq Bras Endocrinol Metab. 2006;50:802). In literature, only one study had been published in 1965 on the cephalometric findings in patients with HVDRR (Marks SC, Lindahl RL, Bawden JW. J Dent Child. 1965;32:259). This is the first detailed study on craniofacial characteristics of patients with HVDRR in the dental literature. The aim of this study was to determine the effect of HVDRR on the parameters of the craniofacial skeleton of young Jordanian patients using cephalometric analysis. Lateral cephalometric radiographs were made for 22 Jordanian children (aged 2,16 years) diagnosed with HVDRR. The cephalometeric parameters of HVDRR group were compared with those of normal control group matched for gender and chronological age using paired t -test. The HVDRR group had a significant increase in the SNBa angle (P < 0·01); as well as reduced anterior cranial base length (P = 0·01), reduced maxillary length, corpus mandibular length and mandibular height (P = 0·01, 0·04 and 0·008 respectively). The cranial base and gonial angles were significantly increased in diseased individual, but the SNA and ANB angles were significantly reduced (P = 0·018 and 0·000 respectively). The angulation of the lower incisor to mandibular plane was also significantly reduced in the diseased group compared with Jordanian norm (P = 0·004). Patients with HVDRR have deficiency in the anterior cranial base length, ramus height and cranial base angle. Patients with HVDRR also have class III skeletal relationship. [source] A simple laser photogrammetry technique for measuring Hector's dolphins (Cephalorhynchus hectori) in the fieldMARINE MAMMAL SCIENCE, Issue 2 2010Trudi Webster Abstract The ability to measure and age individuals within a population has many important applications, for example, for examining growth and determining size class. We developed a simple photogrammetric system using two parallel lasers and a digital camera, in order to measure dorsal fin dimensions of free-ranging Hector's dolphins. Laser dots were projected onto the fin, providing scale, thus allowing measurement as well as simultaneous photo-ID of 34 individuals from fin nicks and other marks. Multiple measurements (,5) were available for six individuals; these resulted in mean CVs of 3.71% for fin length and 3.76% for fin height. Errors due to variations in angle and measurement were quantified via photography of a fiberglass Hector's dolphin model. Allometric measurements and age data were collated from 233 autopsied Hector's dolphins. Using these data, fin length was found to be a better predictor of total length (females r2= 0.732, males r2= 0.678) than fin height. Gompertz age/length growth curves were fitted to these individuals. Linear regressions were used to estimate total length for 34 individuals from laser-metrically estimated fin base length. Individuals were then assigned one of three age categories. This system shows promise as a noninvasive way of measuring individuals, while allowing simultaneous photographic identification. [source] Brain size and the human cranial base: A prenatal perspectiveAMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 4 2002Nathan Jeffery Abstract Pivotally positioned as the interface between the neurocranium and the face, the cranial base has long been recognized as a key area to our understanding of the origins of modern human skull form. Compared with other primates, modern humans have more coronally orientated petrous bones and a higher degree of basicranial flexion, resulting in a deeper and wider posterior cranial fossa. It has been argued that this derived condition results from a phylogenetic increase in the size of the brain and its subcomponents (infra- and supratentorial volumes) relative to corresponding lengths of the cranial base (posterior and anterior, respectively). The purpose of this study was to test such evolutionary hypotheses in a prenatal ontogenetic context. We measured the degree of basicranial flexion, petrous reorientation, base lengths, and endocranial volumes from high-resolution magnetic resonance images (hrMRI) of 46 human fetuses ranging from 10,29 weeks of gestation. Bivariate comparisons with age revealed a number of temporal trends during the period investigated, most notable of which were coronal rotation of the petrous bones and basicranial retroflexion (flattening). Importantly, the results reveal significant increases of relative endocranial sizes across the sample, and the hypotheses therefore predict correlated variations of cranial base flexion and petrous orientation in accordance with these increases. Statistical analyses did not yield results as predicted by the hypotheses. Thus, the propositions that base flexion and petrous reorientation are due to increases of relative endocranial sizes were not corroborated by the findings of this study, at least for the period investigated. Am J Phys Anthropol 118:324,340, 2002. © 2002 Wiley-Liss, Inc. [source] | ||||||||||